Eyeliner is an essential item that is used daily. For me, I don't just use black eyeliner but use dark brown and purple/navy liners as well. I think purple and navy compliment the brown eyes well. I prefer pencil over pen or gel liner because of its ease of use.
Like my mascaras, I tend to buy waterproof ones to minimize the smudging.
For my oily eye lids, I need to use an eyeshadow base to ensure that the liner does not smudge. I almost never line the bottom of my eyes because I think heavy lining at the bottom of your lashes make the eyes look smaller than bigger. I also never line the waterline on the bottom for the same reason, in addition to the fact the liner can smear into your actual eyeballs.
Prestige waterproof eyeliner: cheap, easy to use kohl pencil liner with good color payoff. These are available at London Drugs or Shoppers for under $8. The consistency is smooth and does not smudge much. I always have one in my make up stash.
Clio waterproof eyeliner (brown & black): truly waterproof, budge-proof eyeliners that does not need a pencil sharpener. I have gone through 3 - 4 of these in the last couple of years. The pencil is on the harder side so it may tug the eyelids a bit. If I ever want to line tightline (the white part right below the lashes) I tend to use these ones as they do not smudge at all.
About 8,000 won (~$8).
Dollywink eyeliner: super famous Japanese brand. I bought this because the packaging was too darn cute. The black liner is truly black and it is easy to apply. A little harder than Prestige but softer than CLIO. The downfall is that it smudges.
Rimmel eyeliner (automatic): one of the truest purple eyeliners I have enjoyed over the last 10 years or so. Like the Prestige liner, this one is a permanent part of my make up collection. Very cheap (around $5), readily available and simple to use. It used to have sharpener attached at the back of the pencil but now has a smudger.
The Faceshop Make me star gel pencil liners: another clear winner of non-smudging waterproof pencils. All of them have a fleck of glitter which makes them so pretty. I tend to use the bronze and the navy as a shadow stick.
MAC gel liner (blacktrack): the infamous gel liner that rivals Bobbi Brown gel liner. I don't use this much because this definitely smudges on me. I actually find gel liners not that easy to use. The gel is very soft and smooth but in my opinion, not as easy to control.
E.L.F. felt tip liquid liner: this is $1!!!!!! yes for $1, you get a decent product. Not waterproof, but have not had any issues with smudging or fading. Love this one.
Milani liquify pencil liner: I don't know how they do it but this pencil gives a look of a real gel liners. Super black and super soft. My complaint is that it is too soft and I can never get it to sharpen to a fine point so the lines tend to be thicker than I want. This is also waterproof but has not been completely smudge proof on me.